NBME Gross Anatomy and Embryology 2

Question 1

A patient presents with inability to abduct the arm beyond 15 degrees after a humeral surgical neck fracture. Which nerve is most likely injured?

Accepted Answer

Axillary nerve

Answer

Radial nerve

Answer

Musculocutaneous nerve

Answer

Suprascapular nerve

Question 2

During embryonic development, failure of the pleuroperitoneal membrane to close results in which congenital defect?

Accepted Answer

Congenital diaphragmatic hernia

Answer

Esophageal atresia

Answer

Omphalocele

Answer

Gastroschisis

Question 3

A patient with Colles fracture develops inability to oppose the thumb. Which structure is most likely compressed at the wrist?

Accepted Answer

Median nerve in carpal tunnel

Answer

Ulnar nerve in Guyon canal

Answer

Radial nerve at anatomical snuffbox

Answer

Anterior interosseous nerve

Question 4

Which embryonic structure gives rise to the adrenal cortex?

Accepted Answer

Intermediate mesoderm

Answer

Neural crest cells

Answer

Lateral plate mesoderm

Answer

Endoderm of the urogenital sinus

Question 5

A stab wound to the posterior triangle of the neck results in weakness of shoulder elevation and head rotation. Which nerve is damaged?

Accepted Answer

Accessory nerve (CN XI)

Answer

Phrenic nerve

Answer

Long thoracic nerve

Answer

Dorsal scapular nerve

Question 6

During cardiac embryology, the interventricular septum forms primarily from which structure?

Accepted Answer

Muscular septum growing from apex plus membranous portion from cushions

Answer

Endocardial cushions alone

Answer

Septum primum growing downward

Answer

Neural crest cells migrating into the heart

Question 7

A patient cannot extend the wrist or fingers after a midshaft humeral fracture. Which nerve is injured?

Accepted Answer

Radial nerve

Answer

Median nerve

Answer

Ulnar nerve

Answer

Musculocutaneous nerve